The structures of GS-OH in the 3-Butenyl accessions are illustrated. Gray boxes represent exons, and blue lines represent introns. Black line represents a mutation, and gray lines represent unknown lesions in hypothetical locations. The above mutations create non-functional GS-OH alleles. The fractions of the mutated accessions were calculated out of the total number of 3-Butenyl and OH-3-Butenyl accessions. The observed frequencies were calculated as the ratio between number of accessions with the specific mutation in non-C4 Alkenyl accessions and all the non-C4 Alkenyl accessions, as mentioned in the parentheses.